Remote monitoring of elevator cab lights

摘要

To sense the level of light in the passenger compartment 7 of an elevator cab 8, light at the proximal end of an optical fiber 4 is monitored by an optical detector 25 feeding a variable voltage divider 18, which allows setting a trip point at a desired level of light within the passenger compartment, thereby providing a signal indicating whether the light is adequate or not to a remote elevator monitoring apparatus 23. The trip point may be selected on installation by adjusting a potentiometer while watching an optical indication 17 of reaching the trip point, or it may be determined by software routines.